High severity · published Feb 16, 2023
CVE-2020-6817
bleach.clean behavior parsing style attributes could result in a regular expression denial of service (ReDoS)
7.5
CVSS
0.7%
EPSS
No
On KEV
Description
bleach.clean behavior parsing style attributes could result in a regular expression denial of service (ReDoS). Calls to bleach.clean with an allowed tag with an allowed style attribute are vulnerable to ReDoS. For example, bleach.clean(..., attributes={'a': ['style']}).
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 54% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BL
Bleach · Mozilla
before 3.1.4 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-6817
CVE.org
https://www.cve.org/CVERecord?id=CVE-2020-6817
Exploit
https://bugzilla.mozilla.org/show_bug.cgi?id=1623633
Vendor Advisory
https://github.com/mozilla/bleach/security/advisories/GHSA-vqhp-cxgc-6wmm
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